Cyclic compounds and method of making



Patented Apr. 4, 1950 2,503,011; 7 CYCLIC COMPOUNDS AND METHOD or MAKINGFrederic B. Stilmar, Woodstdwn, and William S. Struve, Carneys Point, N.J., and Ralph N. Lulek, Silverside Heights, Del., asslgnors to theUnited States of America as represented by the United States AtomicEnergy Commission N Drawing.

12 Claims. 1

This invention relates to organic halogen derivatives and is especiallyconcerned with new carbon compounds containing fluorine and chicrine.

It is an object of the invention to prepare new chlorofluoro derivativesof ethylcyclopentane. A further object of the invention is to preparesuch derivatives having a high total halogen content and useful asintermediates for the manufacture of perhalogenated ethylcyclopentanesand other chlorofiuoro compounds. Further objects of the invention willappear from the following description and illustrative examples.

The new compounds of the invention aremonohydro-tridecafluoro-ethylcyclopentane and monohydro-chlorofluoroethylcyclopentanes, of the general molecular formula C'IHFICllIi-I,wherein a: is a positive integer not greater than 13 and preferably atleast 10.

The compounds of the invention are colorless mobile liquids identifiableby their boiling points, molecular weights, and chlorine and fluorineanalyses.

The monohydro tridecafluoro-ethylcyclopentane distills, at 760 mm.mercury absolute pressure, at a temperature of about 64 C.

The monohydro-monochloro-dodecafluoro-ethylcyclopentanes boil, atstandard pressure, at about 94 C.

The monohydro-dichloro-undecafluoro-ethylcyclopentanes boil, at standardpressure, between 110 and 120 C.

The monohydro-trichloro and tetrachloro compounds of the invention boilat progressively higher temperatures up to about 200 C.

The compounds of the invention, while possessing the stability inherentin highly halogenated organic compounds, contain replaceable hydrogen,which permits the production of compounds having various functionalgroups. Moreover the hydrogen atom activates an adjacent halogen atom sothat the compounds are capable of undergoing dehalogenation anddehydrohalogenation in accordance with well-known principles to produceunsaturated compounds or condensation products. Thus they may be reactedin the presence of a copper condensing agent to form substantiallyhigher-boiling chlorofiuoro compounds in accordance with the process ofU. S. Patent application Serial Number 559,230, filed October 18, 1944by Frederic B. Stilmar.

The compounds of the present invention are of particular utility asintermediates for the manufacture of perhalogenated-ethylcyclopentanes.Thus by means of fluorinating agents capable of Application December 20,1945, Serial No. 636,261

replacing the residual hydrogen atoms, for example, cobalt triiiuoride,silver difiuoride, or manganese trifluoride,monohydro-perfluoro-ethylcyclopentanes may be converted toperfluoro-ethylcyclopentane, and monohydro-monochloro dodecafluoro-ethylcyclopentanes andmonohydrodichloro-undecafluoro-ethylcyclopentanes may be converted tothe monochloro-tridecafiuoro-ethylcyclopentanes anddichloro-dodecafluoro-ethylcyclopentanes, respectively. Similarly themonohydro halogenated ethylcyclopentanes of high chlorine content may beconverted to the corresponding pe'rhalogenated ethylcyclopentanes. Theperhalogenated ethylcyclopentanes and the process of making themconstitute the subject of our U. S. Patent application Serial Number636,- 260 filed in the U. S. Patent Oflice on December 20, 1945 andentitled Perhalogenated cyclic compounds and methods of making.

The compounds of the invention may be prepared by fiuorination andcyclization of 2,4- dihydro 3 trichloroethenyl perchloropentane(CIH2C112) and its dehydrohalogenation products (C'zI-IClu and C'zClw).The fluorination may be conducted by means of fluorochlorides ofpentavalent antimony or by antimony pentafluoride.

The 2,4 dihydro-3-trichlorethenyl-perchloropentane employed as astarting material may be obtained by condensing one mol ofhexachloropropene with 2 mols of trichloroethene by the Prins reaction,using aluminum chloride as a condensing agent.

The dehydrohalogenation product, CvHCln, may be obtained in crude formby condensing one mol of carbon tetrachloride with three mols oftrichlorethene in an excess of trichlorethene as solvent at C., usingaluminum chloride as a condensing agent, and segregating the crude 7-carbon fraction by first washing with water to remove aluminum chlorideand then distilling off the excess trichlorethene and those by-productsboiling below about C.

The fluorination of these products may be eifected readily by treatmentwith anhydrous hydrogen fluoride in the presence of antimonypentachloride. The hydrogen fluoride reacts with antimony pentachlorideto form fiuorochlorides of pentavalent antimony and hydrogen chloridegas. Any of the antimony fluorohalides employed as fluorinating agentsfor replacing other organic halogen atoms can be employed to efiect thisreplacement and simultaneous cyclization of the side-chain-substitutedperchloropentane to form the halogenated ethylcyclopentanes of theinvention. In general the antimony halides of the 3 formula SbCl1F5-1,wherein a: has a value from to 2 inclusive, are effective. Ring closureoccurs during the fiuorination with hydrogen fluoride or antimonypentafluoride to form the ethylcyclopentene or ethenylcyclopentanenucleus or both, and probably also the ethylcyclopentane nucleus, andproducts are formed having the molecular formulae, C'zHCI5Fa, CwHChFa,C-zHClsFw, C'rHClzFn, C1HClF12 and C'IHFIS.

For the preparation of halogenated ethylcyclopentanes of relatively highchlorine content, fluorination by means of hydrogen fluoride in thepresence of pentavalent antimony halides as fluorination catalysts ispreferred.

For the production of monohydro-perfluoroethylcyclopentane andmonohydro-monochlorododecafluoro-ethylcyclopentanes, fluorination bymeans of antimony pentafluoride is particularly effective. It istherefore advantageous to prepare these products by a two-step processin which a part of the chlorine of the starting material is replaced byfluorine, employing hydrogen fluoride and an antimony halide catalyst,and these partially fluorinated products, comprising monohydro-dichloroundecafluoro ethylcyclo pentane, monohydro-trichloro-decafiuoro-ethylcyclopentane, monohydro-tetrachloro nonaflu oro-ethylcyclopentane andhalogenated ethylcyclopentanes of still higher chlorine content, are

fluorinated by means of antimony pentafiuoride,

Example 1 One thousand five hundred seventy five parts 01' a2-carbon-side-chain dodecachloroheptene (prepared by condensing one molof hexachloropropene with two mols of trichlorethylene and separatingthe product of 8486 C. melting point) was mixed with 1000 parts ofanhydrous SbCls and 2700 parts of anhydrous HF and the mixture washeated to 150 C. in a steel autoclave. The pressure was kept at 400-450pounds gauge by bleeding the excess gas through a brinecooleddephlegmator. When no further evolution of gas occurred at 150 C.. theautoclave charge was cooled to 20 C. and 2700 parts of anhydrous HF wasadded. The charge was then heated to 150 C. and the pressure wasmaintained at 400- 450 pounds as before. When gas ceased to evolve, thechar e was cooled to 50 C. and excess B1 was distilled oil through adephlegmator maintained at a temperature of about 40 C. The fluorinationproduct was then distilled f om the autoclave at mm. absolute pressure.The vapor temperature rose during the distillation to a finaltemperature of 170 C. Six hundred fortyseven parts of distillate wasrecovered. The distillate was washed with water, dried with calciumchloride, and redistilled at atmospheric pressure. Five hundred threeparts of a yellow oil of boiling range 110-200 C. mostly boiling between135 and 200 C. was obtained. The product had a chlorine content (28% Cl)corresponding to the average formula C-zHClsFm: its boiling rangeindicates that it included C'zHChFo and C-zHClzFu compounds as well asthe trichloro compounds. Monohydro-dichloro perfluoro ethylcyclopen tanemay be obtained by collecting separately that portion of the distillatewhich had a normal boiling point within the range 110-120 C. Thedistillation residue had an average composition corresponding toC-rHChFu. Both the distillate and residue were not completely saturatedand were considered to include compounds of the general formulaeC'IHChFI, CvHClaFs, and C'IHChF'J.

A mixture of 60 parts of a fraction boiling from I 118 to 200 C.obtained as described in the preceding paragraph, and 200 parts ofanhydrous SbF5 was heated at 180 C. for two hours in an aluminum-linedbomb. The mixture was then cooled and poured into a mixture of ice anddilute hydrochloric acid. The organic layer was separated, washedacidfree with water and fractionally distilled at atmospheric pressure.Twelve parts of a fraction boiling from 63.5 to 67 C. and thirteen partsof a fraction boiling from to 100 C. were obtained. The major portion ofthe first fraction boiled between 64 and 65 C. and comprised C'IHF'n;the major part of the 90 to 100 fraction boiled between 92 and 95 C. andcomprised C'IHClFrz.

Example 2 Vapor Temperature Distillate Parts Below 130 C 63 1 881 Above200 C 481 The fraction distilling from 130 to 200 C. is considered tocomprise compounds of the general formulae C7HC12F9, C7HC13F8,C'JHChF'I, C'JHChFn, CvHClaFro, and CvHChFe.

A mixture of 60 parts of the 130200 C. fraction and 200 parts of SbFawas heated for two hours at 180 C. in an aluminum-lined bomb.Distillation of the crude organic product yielded 2 parts of a C1HF13fraction boiling from 56 to 67 C. and 16 parts of a Cil-lClFn fractionboiling from 90 to C.

It will be understood that we intend to include variations andmodifications of the invention and that the preceding examples areillustrations only and in no wise to be construed as limitations uponthe invention, the scope 01. which is deflned in the appended claims,wherein:

We claim:

1. As a new chemical compound, amonohydrotridecafluoro-ethylcyclopentane having a boiling point of about64 C.

2. As a new chemical compound, amonohydromonochloro-dodecafluoro-ethylcyclopentane having a boilingpoint of about 94 C.

3. As a new chemical compound, amonohydrodichloro-undecafluoro-ethylcyclopentane having a boiling pointwithin the range -120 C.

4. The process for making monohyd:o-perhai oethylcyclopentane of highfluorine content, which comprises reacting a compound of the groupconsisting of 2,4-dihydro-3-trichlorethenyl-perchloropentane and itsdehydrohalogenation products, with hydrogen fluoride in the presence ofa fluorochloride of pentavalent antimony at about C.

and at 400-450 pounds gauge until evolution of gas ceases, and reactingthe partially fluorinated organic reaction product at about 180 :C. withantimony pentafluoride to replace at least all but two of the chlorineatoms in the molecule by fluorine atoms.

5. The process for making a monohydro-perfluoro-ethylcyclopentane, whichcomprisesreacting a compound of the group consisting of 2,4-dihydro-3-trichlorethenyl-perchloropentane and its dehydrohalogenationproducts, with hydrogen fluoride in the presence of a fluorochloride ofpentavalent antimony at about 150 C. and at 400-450 pounds gauge untilevolution of gas ceases, reacting the partially fluorinated organicreaction product at about 180 C. with between A and 2 molecules ofantimony pentafluoride for each chlorine atom to be replaced, andseparating from the reaction product a fraction having a normal boilingpoint of about 64 C.

6. The process for making amonohydro-monochloro-perfluoro-ethylcyclopentane, which comprisesreacting a compound of the group consisting of2,4-dihydro-3-trich1orethenyl-perchloropentane and itsdehydrohalogenation products.

with hydrogen fluoride in the presence of a fluorochloride ofpentavalent antimony at about 150 C. and at 400-450 pounds gauge untilevolution of gas ceases, reacting the partiall fluorinated organicreaction product at about 180 C. with between V2 and 2 molecules ofantimony pentafluoride for each chlorine atom to be replaced, andseparating from the reaction product a fraction having a normal boilingpoint of about 94 C.

7. The process for making amonohydro-dichloro-perfluoro-ethylcyclopentane, which comprises reactinga compound of the group consisting of2,4-dihydro-S-trichlorethenyl-perchloropentane and itsdehydrohalogenation products, with hydrogen fluoride in the presence ofa fluorochloride of pentavalent antimony at about 150 C. and at 400-450pounds gauge until evolution 01' gas ceases, and separating'from thereaction product a fraction having a normal boiling point of about110-120 C.

8. The process for making a monohydro-perfluoro-ethylcyclopentane, whichcomprises rcacting 2,4-dihydro-3-trichlorethenyl perchloropentane withhydrogen fluoride in the presence of a fluorochloride of pentavalentantimony at about 150 C. and at 400-450 pounds gauge until evolution ofgas ceases, reacting the fluorinated organic reaction product at about180 C. with between A and 2 molecules or antimony penta- I fluoride foreach chlorine atom to be replaced.

moduct a fraction having a normal boiling pointof aboutBP-C.

presence of a fluorochloride of pentavalent antimony at about 150 C. andat 400-450 poimds gauge until evolution of gas ceases, reacting thepartially fluorinated organic reaction product at about 180 C. withbetween V: and 2 molecules oi antimony pentafluoride for each chlorineatom to be replaced, and separating from the reaction product a fractionhaving a normal boiling poin of about 94 C.

10. The process for making amonohydrodichloro-perfluoro-ethycyclopentane, which comprises reacting2,4-dihydro-3-trichlorethenylperchloropentane with hydrogen fluoride inthe presence of a fluorochloride of pentavalent antimony at about 150 C.and at 400-450 pounds gauge until evolution of gas ceases, andseparating from the reaction product a fraction having a normal boilingpoint of about 110-120 C.

11. The process for making a monohydro-perhalo-ethylcyclopentane whichcomprises reacting a compound of the group consisting of2,4-dihydro-3-trichlorethenyl-perchloropentane and itsdehydrohalogenation products with hydrogen fluoride in the presence of ahalide of pentavalent antimony at about 150 C. and at 400-450 poundsgauge until gas is no longer evolved.

12. As new chemical compounds, monohydroperhaiogenated ethylcyclopentanes selected from the group consisting of amonohydro-tridecafluoro-ethylcyclopentane having a boiling point 01'about 64 C., a monohydro-monochloro-dodecafluoro-ethylcyclopentanehaving a boiling point of about 94 C., and amonohydro-dichloroundecafluoro-ethylcyclopentane having a boiling pointwithin the range 1-10-120 C.

FREDERIC B. STIIMAR.

REFERENCES CITED The following references are of record in the flle ofthis patent:

UNITED STATES PATENTS Number Name Date 2,005,708 Daudt et al. June 18.1085

11. THE PROCESS FOR MAKING A MONOHYDRO-PERHALO-ETHYLCYCLOPENTANE WHICHCOMPRISES REACTING A COMPOUND OF THE GROUP CONSISTING OF2,4-DIHYDRO-3-TRICHLORETHENYL-PERCHLOROPENTANE AND ITSDEHYDROHALOGENATION PRODUCTS WITH HYDROGEN FLUORIDE IN THE PRESENCE OF AHALIDE OF PENTAVALENT ANTOMONY AT ABOUT 150*C. AND AT 400-500 POUNDSGAUGE UNTIL GAS IS NO LONGER EVOLVED.
 12. AS NEW CHEMICAL COMPOUNDS,MONOHYDROPERHALOGENATED ETHYL CYCLOPENTANES, SELECTED FROM THE GROUPCONSISTING OF A MONOHYDRO-TRIDECAFLUORO-ETHYLCYCLOPENTANE HAVING ABOILING POINT OF ABOUT 64*C., AMONOHYDRO-MONOCHLORO-DODECAFLUORO-ETHYLCYCLOPENTANE HAVING A BOILINGPOINT OF ABOUT 94*C., AND AMONOHYDRO-DICHLOROUNDECAFLUORO-ETHYLCYCLOPENTANE HAVING A BOILING POINTWITHIN THE RANGE 100-120*C.